#include <iostream>
#include <string>
#include <functional>

using namespace std;

int main(int argc, char const *argv[])
{
    plus<int> func_plus;
    
    cout << func_plus(10 , 20) << endl; 

    negate<int> func_negate;
    int val = 0;
    cout << "数据取反" << val << " " << func_negate(val);


    return 0;

}
